The present invention relates to an automatic storage system for information recording media, and in particular, to a system and a method in which a plurality of handling apparatuses for automatically achieving mount and/or demount operations of information recording media (to be simply referred to as information media herebelow) are enabled to develop the mount and/or demount operations at a high speed without causing any interference therebetween.
In various fields such as the financial facilities, securities, transportation, and manufacturing industries, there has been developed an automation of respective jobs in an online fashion. With such advancement of jobs, the amount of the respective data items including online data and other related data has been rapidly increasing. In most cases, the user possesses a stock room or storage facility for storing therein a great amount of information media on which data has been recorded such that the system operation is conducted through operations to take out therefrom or to restore therein the media necessary for the daily job.
Heretofore, an operation to take out a necessary information medium from a storage shelf so as to install or to mount the medium in a recording/playback apparatus (to be called a mount operation) and an operation to remove the information medium from the recording/playback apparatus and to restore it in the storage shelf (to be called a demount operation) are carried out as follows in accordance with a manual of the Hitachi Computer Series M, "Comprehensive Operation Management System HOPPS". That is, the user requests the host computer to conduct processing to record data on a medium or to reproduce data from a medium. On receiving the request, the computer system supplies the operator with a medium name, a storage location, a recording/playback apparatus name. Furthermore, when the processing of the medium is completed, there is also reported information including a recording/playback apparatus name associated with the medium and a location to which the medium is to be returned. Based on these information items thus reported, the operator conducts the mount and demount operations. As described above, in case that the operations are manually achieved, it is possible to effect an efficient job only by specifying the medium name, the storage location, and the recording/playback apparatus.
On the other hand, due to an abrupt increase in the volume of the information media to be stored, the number of steps required for the operations to mount and/or to demount information media comes to be considerably great, and hence it is difficult to manually accomplish these operations. In such a situation, attention has been given to an information medium automatic storing system or an automatic storage system for information recording media in which there are provided a storage shelf for storing therein information media, a plurality of recording/playback apparatuses, and a plurality of handling apparatuses to automatically achieve the mount and demount operations. In a case of this automatic storage system, the mount and/or demount operations are effected by the plural handling apparatuses, not by the operators. In general, in a case where operations are effected in a parallel or concurrent fashion by use of a plurality of handling apparatuses, there appear interferences of operations among the apparatuses due to physical restrictions thereof. For example, in a case of a structure where two handling apparatuses travel on a rail, during an operation in which one of the handling apparatuses on the left side of the rail conducts a job in a right end section, it is impossible for the other one of the handling apparatuses on the right side of the rail to initiate a job. Consequently, like in the conventional case, if the computer issues job instructions to the handling apparatuses employed in place of the operators without paying attention to the locations where the operations are to be conducted, there may occur in many cases difficulties as trouble like in the example above, in which the jobs cannot be concurrently achieved and hence the job efficiency is lowered. As a solution to the problem, there has been considered a method in which two rails are disposed to enable the respective handling apparatuses to independently conduct the operations or jobs, thereby improving the physical structure. However, this method is attended with difficulties in practice, for example, due to the restrictions associated with space and cost.